Spiral-broaching mechanism.



R. R.Y LAPOINTE. ,SPIRAL BROACHING MECHANISM. y

APPLICATION FILED MAY I6. I9I2.

1,177,527. Patented Mar. 28,1916.

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y PATENT OFFICE.

RALPH n.l LAPOINTE, or HUDSON, MASSACHUSETTS, AssIGrNonI To LAPoINTE MACHINE Toor. Co., or*v HUDSON, MASSACHUSETTS, A CORPORATION or MAINE.

SPVIRALBRQACHING MECHANISM. f

To all wh-m t may concern:

a citizen of the United States, and resident of Hudson, county of Middlesex, State of 'Massachusetts have invented'an Improvement in Spiral-Broaching Mechanisms, of which the following description, in connection with the accompanyingdrawings, is

a specification, like letters on the drawings representing like parts. n v

The present invention relates to mechanism `for broaching spiral channels or grooves in the walls of the center passages through hollow work-pieces, and in its preferred embodiment is constructed as an appliance adapted for attachment and as- '.semblage with a standard type of broaching machine. J

In the illustrative form ofthe inventionherein shown, my improvements are applied to the well known Lapointe broachingf 3o applied to the head of a broaching machine, a fragmentary portionv of suchhead and the operating draw-screw of the machine being shown broken away; and Fig.

2 is a view partly in elevation and partly in sacentral vertical section, showing essential parts of the improved mechanism, ,other parts being omitted and broken away.

The head or thrust face of the broaching machine is -indicated at 10, and the oper- 40 ating drawfscrew at 11, extending into engagement with a cross-head slide 12, suit-v ably guided in ways from the machine frame. The broach 13, which is shown as of known form provided with a spiral rib 14 gradually rising 'from the bodyl of the broach and interrupted at intervals to form cutting teeth, is secured to the crosshead slide 12 by a key fastening 15, or other `suitable means adapted to impart reciprocation thereto from the operating draw-screw -A and hold it rigidly .against turning. on its ams:

My invention provides means whereby al hollow'work-piece fitted on the broach is Vgiven a controlled rotating movement simul- Specication of Letters Patent.'

`collar 19, and hence effect or Patented Mar 2s, 1916.

Application filed May 16, 1912. Serial No. 697,740.

taneously with the reciprocating movement Be it known that I, RALPH R. LAPOINTE,y

ofthe broach in exactly. the proper, timed relation to correspond with the spiral ineline or pitch of the cutting rib on the broach, so that such' rib will produce a Spiral channel vorgroove or like incline inthe work-piece. To this end a bracket yoke member 16, fixed to the thrust face 10 by flange and bolt clamping means 17, 'is provided with a bearing sleeve 18, within which is fitted a collar 19 having a flange 20 at vone end provided with spiral gear teeth- 21 and threaded at its other end, as seen at 22, v

to receive a bearing or holding ring 23, this ring and the flange 20 serving to hold the collar 19 against displacement relative to the sleeve 18. The collar 19 is shown as having fitted therein a hollow guide member 24 for the broach, this member being provided with a spiral groove or channel 25 off an incline-or pitch corresponding to that of the rib 14 on the broach and of a suitable depth to receive the maximum height of said rib.

A work-'piece a is shown in place on the broach fitting up against the hollow-guide member 24, which is vshown as anged at a projecting portion .28 engaging with a lug 29 on the end of the collar19. To impart the requisite `definite rotary movement to the collar 19, I mount a spiral gear 30 fixed on'a shaft 31 to mesh with the spiral gear 21in bearings on a bracket 32 extend,

ing up from the bearing sleeve 18, and on the shaft 31 a spur gear. 33 is also xed-and arranged to mesh with a rack 34 formed on the under surface of a bar 35, rigidly.

mounted on a vpost 36 upstanding from and rigid with the cross-head slide 12, this rack being usually heldin mesh-by a guiding -member (not shown). vThus,- as the crosshead reciprocates, the` rack 34 will operate \the` gear 33, and thence v through the spiral gear connection 30, 21 `effect turning of the ing ofthe work-piece a. It will be` understood that gear connectionsv are so 4proportioned that the described as imparted from the operating screw is permit turn- 'the reciprocatory movement of the rack 34, l

effect theturning of the collar 19 at a rate relative to the rate of reciprocatory movement of the breach, so that a given peint on the breach will travel relative te the collar, and hence te the work-piece, in a di. rection to describe the same spiral incline or pitch as that of the spiral rib on the breach. Thus such spiral rib will produce a spiral channel or groove in the work-piece et an incline or pitch the same as its own, in an expeditious and effective manner, and with a minimum of unnecessary friction or lost power. With the gearing connections correctly proportioned as described, it is further possible to -produce a channel or groove of accuratel dimensions and 'clean cut of a size and depth as determined by the dimensions of the cuttingrib by which it is produced.

I am aware that variations in details of vrconstruction may be resorted to without departing from the spirit of 'the invention,

and I therefore do not desire to be limited as to these or in any other way, except as set forth in the appended claims.

`I-Iaving described my invention, what I claim as new, and desire to secure by Letters Patent is: l

1. Apparatus of the kind described, cemprising a breaching machine head, a* breach having a cutting projection formed and adapted for operation en reciprocatien of the breach, means for applying power to the apparatus for reciprocating the breach while holding it against rotation, and means for rotating a work piece mounted on said breaching machine head in timed relation to the reciprecation of the breach for pro ducing a spirally breached cut.

2. Apparatus of the kind described, cemprising a breaching machine head, a breach having a cutting rib formed as a relatively open spiral, means for applying power -to the apparatus for"'1'eciprocating the breach while holding it against rotation, a work movement of the broach, means for applying power to the apparatus for reciprocating the breach,.a collar through which said breach passes mounted to rotate on the face of said breaching' machine head "having provision for controlling the turning of a work piece mounted on the breach, and geared connections from said breach reciprocating means for eiiecting timed rotation of said. collar relative te the reciprocation of said breach whereby a spiral path is breached in the work.

4. Apparatus of the kinddescribed, cemprising a breach provided with relatively open spiral cutting elements adapted te operate on rendwise movement of thebroaoh, means for reciprocating said breach and holding it against rotation, a collar mounted to turn and having said breach. passed therethrough, said collar being equipped with provision for controlling the rotation f of a work-piece onfsaid. breach, andfgeared connections from said breach reciprocating means for effecting timed rotation of Said collar relative to the breach reciprocatien, including a rack carried by the breach reciprocating means.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

RALPH R. L APOINTE.

Witnesses:

C. L. ROGERS, R. HERSEY. 

